One would be remiss if the story of the popular 19th century pigment Indian Yellow were not told. A preface to this story is the understanding of the transition from manufacturing products made with readily found ingredients using semi-sophisticated methods to the burst of scientific discovery and industrial expansion fueled by discoveries in chemistry and physics. In 1669 only 14 elements were known. By 1800, an additional 17 were discovered. By 1900, an explosion of 52 elements were uncovered. To be fair, many of the elements from 1800 to 1900 were born of research on radioactive materials and do not have practical use for consumer goods we use on a daily basis.
Indian Yellow had its “feet” planted firmly in the unsophisticated, pre-chemical, pre-industrial revolution period. The historic origins of this pigment came from the documentation assembled by D.J. Hooker, a botanist and director of Kew Gardens in the U.K. In 1882, Hooker was asked to trace the roots of Indian Yellow. Having spent time in India where the pigment was reported to come from, Hooker, corresponded with T.N. Mukherji in Calcutta to learn about the manufacture of this pigment. Mukherji journeyed to Munger where he witnessed and then documented the production of Indian Yellow. The absence of any other historical reference other than Mukherji, around 19 years ago, generated the rumor that the story behind the production of Indian Yellow was fabricated. For some skeptics the origin of Indian Yellow was unusual and too odd to be true, especially when only one single reference was documented.
One important skeptic was Victoria Finlay. Her book, “Color, A Natural History,” questioned the validity of the story behind Indian Yellow simply because only one reference source written by Mukherji has ever been cited. My own personal interaction with Victoria Finlay came a year or so before the publication of her book. We spent the day together discussing pigments, focusing a great deal on Cochineal, commonly know as the color Carmine. I read drafts of several chapters and provided feedback to Victoria to edit a few interpretations of her research, but to no avail, some unusual statements came out in her book. (Despite my never suggesting that, Carmine is “raw” bug blood, but rather an extraction of the essence of the biological makeup of cochineal. The words, “Bug blood” were far more interesting to a reader than the actual chemical process of making Carmine pigment.)
With regards to Indian Yellow, Finlay stated her skepticism of the validity of the pigment being derived from harvesting the urine of cows fed a diet of mango leaves with a bit of turmeric added to their unnatural and unhealthy fodder. View through the “lens” of the 21st century, the practice of using cows to produce a pigment seemed to be born from fantasy despite its adoption and popularity among artists. It became a staple on artists’ palettes to the extent that it was even referred to as Turner’s Yellow because J.M.W. Turner’s extensive use of the color.
So does Indian Yellow really come from refined cow urine fed with a copious amount of mango leaves, or is the name and origin just another flight of fancy, like calling the dark red resin pigment derived from the Dracaena species, “Dragon’s Blood.”
Thankfully, the mystery has been resolved. The 19th century analysis of Indian Yellow revealed a high percentage of euxanthic acid, (a combination of glucuronic acid and euxanthone.) The presence of these two chemicals unmistakably point to the animal origin of this material. The background and scientific analysis of Indian Yellow is referenced by N.S. Meena, 6-27-2020 in an article in the website Medium. The proof for the origin of Indian Yellow is derived from a paper published in 2016 by two materials research scientists, R. Ploeger and A. Shugar who analyzed documented samples of Indian Yellow. Rebecca Ploeger also happened to be a fellow in the scientific research department at the National Gallery of Art during my time at the Gallery. Rebecca further studied the effects of zinc on delamination of paint films on primed canvases. But that is a story for another time.
So, despite only one reference that Hooker made in the 19th century from a report drafted by Mukherji, cow urine was transformed into a vibrant, transparent yellow pigment. In a strange social/political/ethical twist, Britain, the country that used the most Indian Yellow, abided by a ban on the production of the pigment because the Government of India passed a law in 1890 to stop any practices that were cruel to animals. This included feeding mango leaves to cows.
I recall gazing with envy at the display of Indian Yellow I saw in an exhibition case in the lobby of the Winsor and Newton headquarters in 2006 when visiting the manufacturer in Harrow/Wealdstone, just a short train ride from London. Three or four classic “balls” of Indian Yellow the size of baseballs rested in a stemmed crystal dish. These were one of many amazing items stored in Winsor and Newton’s infamous attic. Ledger books, pigment samples, letters and notes from suppliers all carefully stored, collecting dust. The ultimate fate of the Winsor and Newton attic, materials and the changes that occurred after 2006 are a topic for another essay adventure.
So comes an end to another tale of intrigue that involves a biological waste product. There are a few more stories about the intersection of biology and pigments that will be told in future Syntax articles. Until then, enjoy your far more stable, permanent, Indian Yellow paint you have in your possession, free from any harm done to animals in the production of this color. References to a limited color palette composed of Indian Yellow, Ultramarine Blue and Quinacridone Magenta can serve as a wonderful 3 basic color selection to use in paintings. Indian Yellow’s modern incarnation is an amazing, versatile pigment in an artist’s arsenal of colors. So the next time you pass a cow when driving in the countryside, thank them for providing the biological means that inspired the creation of such a wonderful pigment.
The Syntax of Color
Syntax of Color Essay 3-22-2021